A passenger boarding bridge is a bridge in the form of a machine for transferring passengers between an airplane and an airport terminal. Typically, the passenger boarding bridge includes a fixed tunnel installed from the terminal to a rotunda and a movable passenger boarding bridge installed between the rotunda and the airplane, and can change a direction and move to be adjacent to an air bridge by using wheels of the movable passenger boarding bridge. Typically, the passenger boarding bridge is formed of an inner tunnel and an outer tunnel. By moving the outer tunnel to accommodate the inner tunnel therein, a length of the movable passenger boarding bridge can be regulated.
The airport terminal and the airplane run adequate air-conditioning and heating. However, a wall of the passenger boarding bridge is manufactured from glass in most cases, and outside air flows through a rotunda area, above a cabin, and through gaps between the inner tunnel and the outer tunnel of the movable passenger boarding bridge, and, thus, a temperature in the passenger boarding bridge is higher or lower than an adequate temperature, which provokes complaints from passengers. In order to solve such problems of inconvenience, various air-conditioning and heating systems have been installed at the passenger boarding bridge.
For example, one of conventional air-conditioning and heating apparatuses for a passenger boarding bridge is installed at a fixed tunnel without limitation in installation position. Such an air-conditioning and heating apparatus for a passenger boarding bridge employs a packaged air-conditioning and heating apparatus for a general building with a low flow rate, which makes air feel cool or warm just under a place where an indoor unit is installed but cannot evenly air-condition and heat the inside of the tunnel even if the air-conditioning and heating apparatus is operated all day long.
Further, as for an air-conditioning and heating apparatus for a passenger boarding bridge installed at an upper part of the outer tunnel on the airplane side, when the passenger boarding bridge is minimized, a diffuser installed inside the outer tunnel is covered with the inner tunnel and air cannot be introduced into the outer tunnel.
Another conventional air-conditioning and heating apparatus for a passenger boarding bridge is as described in Korean Patent Laid-open Publication No. 10-006770 (Jun. 25, 2009) in which an air-conditioning and heating apparatus is installed at an upper part of the outer tunnel on the airplane side and an air-conditioning apparatus is installed at the inner tunnel on the rotunda side. To be specific, such an air-conditioning and heating apparatus for a passenger boarding bridge is installed at an upper part of a rotunda, and, thus, cooled and heated air can be transferred to the inside of an inner tunnel through a duct and a diffuser configured to transfer cooled and heated air to the inside of the inner tunnel, and at the end on the outer tunnel side of the diffuser provided within the inner tunnel, the diffuser is provided in a direction toward an outer tunnel, and, thus, cooled and heated air is supplied into the outer tunnel. Such an air-conditioning and heating apparatus for a passenger boarding bridge cannot transfer sufficient cooled and heated air to the outer tunnel since the duct can be installed only at the inside of the inner tunnel.
Further the movable passenger boarding bridge is transversely and vertically rotated around the rotunda. However, such an air-conditioning and heating apparatus is very limited in supplying cooled and heated air since a pipe connecting the air-conditioning and heating apparatus at the rotunda and the duct at the inner tunnel may be damaged as the movable passenger boarding bridge is rotated.
Furthermore, the outer tunnel may be moved toward the inner tunnel in order to minimize a length of the passenger boarding bridge as necessary. If the inner tunnel is moved into the outer tunnel, there is no sufficient space for installing an air-conditioning and heating apparatus at an upper part of the inner tunnel.